Yes,but it depends on how you look at it.
My local Lexus dealer in Sweden said a long time ago that the only reason why Lexus is waiting with the new IS,is the new BMW 3 series.They wanted to see exactly what that car would look like ( performance,engines,technology and so on) before they introduced the new IS in europe.He also said "when BMW releases the 3 series,Lexus will release the IS".And thats exactly what will happen.The 3 series will also debute att Geneva Auto saloon.
The reason why people says 2006 is becuase it will be sold in the USA as a 2006 year model.But it will be at the dealers in late nowember i EU.In japan the car will be on the road in august/september.
Sorry, my english is bad ,im from sweden :)